Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] Apply memory policies to top two highest zones when highest zone is ZONE_MOVABLE | Date | Sat, 4 Aug 2007 10:51:13 +0200 |
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> It only affects hot paths in the NUMA case so non-NUMA users will not care.
For x86-64 most distribution kernels are NUMA these days.
> For NUMA users, I have posted patches that eliminate multiple zonelists > altogether which will reduce cache footprint (something like 7K per node on > x86_64)
How do you get to 7k? We got worst case 3 zones node (normally less); that's three pointers per GFP level.
> and make things like MPOL_BIND behave in a consistent manner. That > would cost on CPU but save on cache which would (hopefully) result in a net > gain in most cases.
That might be a good tradeoff, but without seeing the patch the 7k number sounds very dubious.
> I would like to go with this patch for now just for policies but for > 2.6.23, we could leave it as "policies only apply to ZONE_MOVABLE when it > is used" if you really insisted on it. It's less than ideal though for > sure.
Or disable ZONE_MOVABLE. It seems to be clearly not well thought out well yet. Perhaps make it dependent on !CONFIG_NUMA.
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